1. Technical Field
The present invention related to a reverse insertion preventing connector for accommodating a male terminal part to be electrically mated with a female connector, and more specifically to a reverse insertion preventing male connector housing which can prevent the male terminal part from being inserted thereinto in the reverse direction.
2. Description of the Related Art
FIGS. 1, 2, 3A and 3B show a prior art reverse insertion preventing connector 1 disclosed In Japanese Published Unexamined (Kokai) Utility Model No. 62-30292. In FIGS. 1 and 2, the reverse Insertion preventing connector 3 is roughly composed of a connector housing 1 and a terminal part 7. In more detail, the connector housing 3 is formed with a terminal accommodating chamber 5. In this connector housing 3, a flexible engage arm 9 is formed so as to be engaged with the terminal part 7 inserted into the terminal accommodating chamber 5. The flexible engage arm 9 extends from the inner wall 11 of the connector housing 3 toward an opening side thereof so as to form a space between the engage arm 9 and the inner wall 11 in which the engage arm 9 can be deformed. Further, the flexible engage arm 9 is formed with an engage end surface 21, a reverse insertion preventing projection portion 13 at a free end thereof, and a reverse insertion preventing block portion 15. These reverse insertion preventing projection and block portions 13 and 15, respectively, have terminal contact surface portions 13a and 1Sa, respectively, an end 7a of the terminal part 7 being brought into contact with each portion 13a and 15a when the terminal part 7 is inserted into the connector housing 3 in the reverse direction.
On the other hand, the terminal part 7 is roughly formed with a wire clamping portion 17 and a fiat electric contact portion 19. The fiat electric contact portion 19 is formed by bending a plate into a flat cylindrical shape in such a way as to fit into the inner wall of the connector housing 3.
When the terminal part 7 is inserted into the terminal accommodating chamber 5 normally (in the normal direction), as shown in FIG. 2, since the engage end surface 21 of the flexible engage arm 9 is engaged with an engage shoulder portion 23 of the terminal part 7, the terminal part 7 can be accommodated and held in position within the terminal accommodating chamber 5 of the connector housing 3.
In contrast with this, when the terminal part 7 is inserted into the terminal accommodating chamber 5 abnormally (in the reverse direction) as shown in FIG. 3, since an end portion 7a of the terminal part 7 is brought into contact with the terminal contact surface portion 15a of the reverse insertion preventing block portion 15, it is possible to prevent the terminal part 7 from being inserted into the connector housing 3 in the reverse direction. In addition, in case the terminal part 7 inserted in the reverse direction is inserted forcibly beyond the reverse insertion preventing block portion 15 as shown in FIG. 3B, since the end portion 7a of the terminal part 7 is further brought into contact with the terminal contact surface portion 13a of the reverse insertion preventing projection portion 13, it is possible to prevent the terminal part 7 from being inserted into the connector housing 3 in the reverse direction. In other words, the terminal part 7 can be doubly prevented from being inserted into the connector housing 3 in the reverse direction securely.
In the above-mentioned prior art reverse insertion preventing connector 1, however, since the reverse insertion preventing block portion 15 is formed at the base portion of the flexible engage arm 9 and thereby the wall thickness of this block portion 15 is relatively large, there exists a problem in that the flexibility of the engage arm 9 is insufficient and therefore the engage arm 9 is easily damaged when deformed excessively.
In addition, since the contact portion 15a of the engage arm 9 is formed on the insertion side of the terminal part 7, even when the terminal part 7 is inserted into the terminal accommodating chamber 5 in the normal direction, the end portion 7a of the terminal part 7 tends to be brought into contact with or caught by the contact portion 15a of the engage arm 9, thus causing another problem in that the terminal part 7 cannot be inserted smoothly into the terminal accommodating chamber 5.